Soft tissue defect repair device

ABSTRACT

An inguinal hernia repair device in the form of an implantable plug that is affixed at one end to the center region of a sheet of implantable material. The plug takes the form of a plurality of hollow members, arranged so as to be in substantially parallel relationship when implanted into a defect. The hollow members are preferably tubular members and are preferably bundled together by various means, such as bonding or wrapping a band or strand about the plurality of hollow members to maintain them in adjacent and contacting relationship during insertion into a defect.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of soft tissue defectrepair devices, and more particularly to the field of inguinal herniarepair devices.

BACKGROUND OF THE INVENTION

[0002] The repair of inguinal hernias is one of the most commonlyperformed surgical procedures. Various prosthetic materials, typicallyporous to allow for tissue ingrowth, have been provided in a variety ofcombinations, forms and shapes. Surgical mesh, typically ofpolypropylene, has been commonly used, in some instances having beenrolled up into a cylindrical shape and inserted into the defect as aplug. To reduce the tendency to migrate, these plugs are sometimesaffixed at one end to the center of a sheet of material. The sheet isused to overlap the defect and for attachment to the adjacent tissue toreduce the likelihood of migration of the device; see, for example, U.S.Pat. No. 5,116,357 to Eberbach and U.S. Pat. No. 5,147,374 to Fernandez.These sheet-and-plug devices lend themselves to laparoscopic repair asthey may be inserted via a trocar wherein, after insertion, the edges ofthe sheet may be fastened to the tissue adjacent the defect.

[0003] Hernia repair plug devices have been refined into a variety ofshapes. One such commercially available device is the PerFix® Plug fromC. R. Bard, Inc. (Murray Hill N.J.), described in U.S. Pat. No.5,356,432 to Rutkow et al. and in revised form by U.S. Pat. No.5,716,408 to Eldridge et al. This device is in the form of a pleatedconical fabric mesh provided with additional mesh filler material withinthe hollow of the cone; a sheet of material is not attached to the plug.There are reported cases of devices of this type having migrated fromthe site of the defect. Further, the mesh filler material is often notadequate to provide the necessary axial stiffness and radial complianceto the conical form. These attributes are desirable in order to aid inthe insertion of the device into a hernia defect (In the axial directionwith regard to the device) and to better enable the device to fill thedefect in the radial direction.

[0004] U.S. Pat. No. 6,425,924 to Rousseau teaches two opposing conicalmesh shapes fitted together on a common axis and separated by one ormore tubular components also on the common axis, with the apices of thetwo cones pointed away from each other. The apex of one cone is affixedto the center of a sheet of mesh material.

[0005] Various materials have been discussed for use as prosthetic plugsfor the repair of inguinal hernias. Polypropylene andpolytetrafluoroethylene are commonly discussed. Polypropylene is mostoften used in the form of a woven or knitted mesh fabric to create thedesired shapes. Polytetrafluoroethylene is typically used in its porous,expanded form, usually noted as ePTFE. Other described non-absorbablematerials include cotton, linen, silk, polyamide (e.g., nylon 66) andpolyethylene terephthalate. Various absorbable materials have also beenproposed, including homopolymers and copolymers of glycolide andlactide, caprolactones and trimethylene carbonates. See, for example,U.S. Pat. No. 6,113,641 to Leroy et al., U.S. Pat. No. 6,180,848 toFlament et al. and U.S. Pat. No. 6,241,768 to Agarwhal et al. While theliterature contains suggestions to manufacture hernia repair plugs fromabsorbable materials, the present inventors are unaware of any suchabsorbable plugs having ever been made commercially available.

[0006] Further, there remains a need for a repair plug that possessesadequate axial stiffness and radial compliance, and encourages rapidhealing of the defect.

SUMMARY OF THE INVENTION

[0007] The present invention is an inguinal hernia repair device in theform of an implantable plug that is affixed at one end to the centerregion of a sheet of implantable material, with the length of the plugcomponent oriented to be substantially perpendicular to the sheet. Theplug takes the form of a plurality of hollow members, arranged so as tobe in substantially parallel relationship when implanted into a defect.The hollow members are preferably bundled together by various means,such as bonding or wrapping a band or strand about the plurality ofhollow members to maintain them in adjacent and contacting relationshipduring insertion into a defect.

[0008] The hollow members are preferably tubular. The use of a pluralityof tubular members provides for good axial stiffness, beneficial duringinsertion into the defect, in combination with good radial compliancedue to the transverse compressibility of the relatively thin-walledtubes. Preferably, a plurality of discrete, individual tubes are used,with at least one end of each tube remaining open to allow rapid accessfor body fluids and living cells. The open end of the tube is located atthe end of the plug opposite the end that is affixed to the sheet ofimplantable material. As noted above, the plurality of tubes may beaffixed at one end to the center region of a sheet of implantablematerial. The purpose of the sheet is to provide stabilization of thedevice by anchoring in the preperitoneal space, thus ensuring properplacement of the plug.

[0009] In a preferred embodiment, the tubular members are about twicethe desired length of the plug component. Each tube is folded in half atthe midpoint of its length, with all tubes attached at the fold to thesheet component. The plurality of folded tubes is then bundled togetheras described above.

[0010] The hollow members and the sheet component may be made from anysuitable implantable materials including both absorbable andnon-absorbable materials. The entire device may be made to benon-absorbable, or alternatively the entire device may be made to beabsorbable. The plug may be made to be absorbable and affixed to anon-absorbable sheet, or vice versa. Absorbable materials are preferred,particularly for the plug component, in that they are anticipated toelicit an inflammatory tissue response that may result in more rapidhealing. It is apparent that absorbable materials with differingabsorption rates may be used for various different components of thehernia defect repair device.

[0011] If desired, the length of the hollow members may be reduced bytrimming with a cutting tool.

[0012] A preferred material for either or both of the sheet and plugcomponents is a copolymer of poly(glycolide:trimethylene carbonate). Thecopolymer's polyglycolide component is commonly abbreviated as PGA forpoly(glycolic acid), the chemical byproduct to which it degrades afterhydrolysis. The poly(trimethylene carbonate) component is commonlyabbreviated as TMC, with the copolymer itself typically referred to asPGA:TMC accompanied with relative percentage composition by weight. Thepreferred PGA:TMC copolymer embodiment is in the form of a non-woven webas taught by Hayes in U.S. Pat. Nos. 6,165,217 and 6,309,423. Anotherpreferred embodiment involves the use of a PGA:TMC plug with a sheet ofePTFE. Alternatively, the sheet may be a composite sheet of ePTFE andPGA:TMC.

[0013] Either or both of the sheet component and the plug component mayoptionally be treated (e.g., impregnated or coated) with any of variousbioactive agents such as antimicrobials or antibiotics. This is possibleregardless of whether the material used for the treated component isabsorbable or non-absorbable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a perspective view of a hernia repair device of thepresent invention.

[0015]FIG. 1A is a side view of a method of making the device of FIG. 1.

[0016]FIGS. 1B and 1C are top views further illustrating the method ofFIG. 1A.

[0017]FIG. 2 is a perspective view of an alternative hernia repairdevice of the present invention wherein a corrugated sheet is rolled tocreate the plug component.

[0018]FIGS. 2A and 2B are upper and lower perspective views of thecorrugated sheet prior to rolling up to create the plug.

[0019]FIG. 3 is an end view of an embodiment wherein the hollow membershave hexagonal transverse cross sections.

[0020]FIG. 4 is a perspective view of a hernia plug incorporating a barbcomponent around the circumference of the plug.

[0021]FIG. 5 is a perspective view of an embodiment of the hernia repairdevice incorporating a layered sheet component

[0022]FIG. 5A shows a cross section of a composite sheet material foruse with the hernia repair device.

[0023]FIG. 6 is a longitudinal cross section that describes analternative way to accomplish the attachment of the plurality of hollowmembers to the sheet component.

DETAILED DESCRIPTION OF THE INVENTION

[0024]FIG. 1 is a perspective view of a hernia repair device 10 of thepresent invention, wherein a plurality of hollow members 12 are providedin substantially parallel relationship, creating plug 14. Preferably,hollow members 12 are tubular as shown in this embodiment. Optionallyand preferably, one end of plug 14 is affixed to the approximate centerof a sheet 16 of implantable material. Sheet 16 may optionally beprovided with one or more slits 17 as desired to increase flexibility ofsheet 16 and to better enable it to be folded as necessary forinsertion.

[0025] Hollow members 12 are not required to be tubular. Consequently,each hollow member 12 is not required to have either a round orcontinuous (uninterrupted) circumference. The hollow members may, forexample, be tubes provided with a slit along all or a portion of theirlength in order to further increase their radial or transversecompressibility. While round transverse cross sections are preferred,other shapes such as square, rectangular, hexagonal, elliptical, etc.may be used. The transverse cross sectional shapes of the hollow membersmaking up an individual plug may all be the same, or two or moredifferent transverse cross sectional shapes may be used in combinationto make up a single plug.

[0026] Hollow members 12 are preferably provided in a bundle thatresults in their being substantially parallel to each other wheninserted. By “substantially parallel” in this context is meant that thehollow members vary only about ±20 degrees, and more preferably onlyabout ±10 degrees, from perfectly parallel. The hollow members may bemaintained in a bundled relationship by various bundling means, such asbonding together outer surfaces of adjacent hollow members or wrapping aband 18 or strand about the plurality of hollow members 12 to maintainthem in adjacent and contacting relationship during insertion into adefect. The bundled relationship may also result from the means used toaffix the individual hollow members 12 to a sheet 16.

[0027] For embodiments wherein plug 14 is fabricated from an absorbablematerial, band 18 or any other suitable bundling means may be made froma material that absorbs or dissolves faster than the material of plug14. As such, band 18 (or other bundling means) can be expected to absorbor dissolve before the plug and will release the substantially hollowmembers to allow them to better conform to the shape of the defect intowhich they were inserted when contained by the bundling means.

[0028] Hollow members 12 have opposing ends wherein one end of each ofthe plurality of hollow members remains open, thereby allowing access ofbody fluids and cells into the luminal space of each hollow member. Thisis anticipated to increase the rate of tissue attachment and healing,particularly if the hollow members 12 comprise an absorbable material.The end of each hollow member 12 opposing the open end may be affixed tothe central region of sheet 16.

[0029] Alternatively, as shown by FIG. 1A, each hollow member 12 may beof a length that is about twice the length of plug 14, whereinindividual hollow members 12 are folded in half transversely (indicatedby arrows 22) at about the midpoint of their length, and attached at thefold to sheet 16.

[0030] Attachment of hollow members 12 to sheet 16 may be accomplishedin a variety of manners, depending on the configuration of hollowmembers 12 and the materials selected for the hollow members 12 andsheet 16. The various affixing means include the use of adhesivessuitable for the chosen materials, various mechanical attachment meanssuch as sewing with suitable materials (e.g., suture materials), orwelding means such as the appropriate application of heat, solventwelding or by ultrasonic welding.

[0031] A preferred method of making the embodiment with folded hollowmembers is shown in the top views of FIGS. 1B and 1C. FIG. 1B shows howa hollow member 12 may be provided with opposing notches 24 along itssides to better enable additional hollow members to be stacked at thesame attachment point as further shown in FIG. 1C. Notches 24 reduce theinterference resulting from multiple hollow members 12 being attached atdifferent angles at the common location. It is apparent that a pluralityof hollow members 12 may be attached at the common location in thismanner. The hollow members may be further provided with a hole 26 at thecenter of the transverse fold line to accommodate a temporary locatingpin (not shown for clarity; for use only during fabrication until theassembly is complete). Conversely, such a locating pin might be madefrom a suitable absorbable material and remain in place as a part of thedevice construction.

[0032]FIG. 2 is a perspective view of an alternative hernia repair plugof the present invention describing an embodiment wherein the hollowmembers 12 are in the form of a corrugated material 32 that is rolled upor otherwise bundled to form plug 14. The corrugated material 32 may berolled up to create the plug 14 or simply folded and bundled by wrappingwith a band 18 or my other means described previously. Plug 14 isaffixed to sheet 16 as described previously. For any of the embodimentsdescribed herein, the resulting juncture of plug 14 and sheet 16 may beoptionally reinforced by a fillet component 39. Fillet 39 is simply adisc of suitable material fitted around the base of plug 14 with enoughinterference to cause it to fit tightly around the base of plug 14.Fillet 39 may be joined to sheet 16 and plug 14 by various affixingmethods described previously. Alternatively, sheet 16, fillet 39 andband 18 may be formed of a single piece.

[0033]FIGS. 2A and 2B show respectively upper and lower perspectiveviews of a corrugated sheet material suitable for rolling or otherwisebundling to create plug 14. The corrugated sheet 32 comprises an upperlayer 34 that is corrugated and affixed to a planar lower layer 36 byany suitable means. The corrugations result in a plurality of hollowmembers 12. Rolling of the corrugated sheet 32 to create plug component14 is accomplished by rolling in a direction transverse to the length ofthe corrugations. As shown by FIG. 2, this results in the corrugationsthat provide the plurality of hollow members 12 extending along thelength of the cylindrical plug 14, parallel to the longitudinal centerline of the plug 14. The ends of the corrugations, opposite the end ofthe plug that is subsequently affixed to sheet 16, remain open. Thecorrugated sheet material 32 may be made from any desired absorbable ornon-absorbable material. These corrugated sheets are anticipated to haveother implantable applications in addition to use as the plug componentof the hernia repair device described herein. For example, thecorrugated sheet material 32 may be useful in planar form for the repairof various tissue defects where a somewhat flexible, but “reinforced”sheet is desired. They may also have utility when rolled up to create acylindrical shape appropriate for other applications. The hollow membersresulting from the corrugated construction may be beneficial for variousimplantable applications.

[0034] Optionally, as shown by FIGS. 2A and 2B, corrugated sheetmaterial 32 may be provided with one or more transverse corrugations 38on the lower surface of planar lower layer 36. When the corrugated sheetmaterial is rolled up to create plug 14 of FIG. 2, these corrugations 38become barbs or anchoring features extending circumferentially aroundthe outer surface of plug 14, as will be further described. Corrugations38 must be adequately flexible or distortable to allow the corrugatedsheet 32 to be rolled up in the direction of their length. If desired,corrugations 38 may be cut transversely at intervals along their lengthto better enable the corrugated sheet 32 to be rolled up

[0035]FIG. 3 shows a top view of plug 14 wherein the hollow members 12have hexagonal transverse cross sections. Plug 14 may result frombundling a plurality of individual hollow members 12 or alternativelythe members may be provided by extrusion of a honeycomb form whereinadjacent hollow members 12 share common walls. It is apparent thathollow members 12 may be provided in a variety of cross sectionalshapes.

[0036]FIG. 4 shows a perspective view of a plug 14 provided with a band18 that includes one or more barbs 42, intended to aid in the securementor anchoring of plug 14 within a tissue defect. Additionally, barbs 42may serve as the band component 18 that holds hollow members 12 togetherin a bundle. These barb components 42 may be made in a variety of ways.FIG. 4 shows two barbs made from discs of absorbable material andprovided with flanges 44 that enable the attachment of barbs 42 to theouter surface of plug 14. These anchoring barbs 42 may also be made byproviding transverse corrugations 38 to corrugated sheet 32 prior torolling corrugated sheet 32 to form plug 14, as described previously andshown in FIGS. 2A and 2B.

[0037]FIG. 5 shows a perspective view of an alternative embodimentwherein sheet 16 is provided in two or more layers which may optionallybe attached (e.g., laminated) together to create a composite sheetmaterial 51 wherein the two layers have different properties. In apreferred embodiment, composite sheet material 51 includes anon-absorbable layer 53 and an absorbable layer 55. In use, absorbablelayer 55 is placed in contact with the tissue adjacent the defect. Thenon-absorbable layer 53 is preferably ePTFE and the absorbable layer 55is preferably PGA:TMC as taught by the Hayes patents referred to above.

[0038]FIG. 5A shows a cross section of an alternative composite sheetmaterial 51 wherein the non-absorbable layer 53 has opposing surfaces 57and 59 with different characteristics, for example, surface 57 beingrougher and/or more open than surface 59. Rougher surface 57 is intendedto encourage long term tissue attachment and ingrowth while smoothersurface 59 is intended as a barrier to tissue attachment and ingrowth inorder to prevent or reduce the likelihood of tissue adhesions. If layer53 is a porous material, then smoother surface 59 may be provided with asuitably small pore size while rougher surface 57 may be provided with asuitably larger pore size. If desired, sheet 16 may be the result ofattaching two different layers together (as by bonding with an adhesiveor melt bonding, or by mechanical fastening means such as sewing) toachieve the desired different surface characteristics. Rougher surface57 is preferably provided with a covering or coating of absorbable layer55; when this layer 55 is bioabsorbed after a suitable time, roughersurface 57 remains to provide the desired long term tissue attachment.The presence of the bioabsorbable layer 55 is anticipated to enhancehealing as a result of the increased inflammatory tissue response to theabsorbable material. This may be desirable due to the chemically inertcharacter of the PTFE material (which consequently does little to elicita biological reaction from adjacent tissue when implanted by itself).

[0039] It is also apparent that the bioabsorbable layer 55 may beprovided on one surface of an ePTFE material having similar opposingsurfaces, as well as providing such an absorbable layer on one surfaceof a differentially-sided ePTFE material.

[0040] A preferred material for the non-absorbable layer 53 is Gore-TexDual-Mesh™ with Corduroy™ surface (Flagstaff Ariz.); this material hasopposing surfaces with different tissue attachment and ingrowthcharacteristics as described above.

[0041]FIG. 6 is a longitudinal cross section of a band 18 that has beenflared using suitable tooling to create the bioabsorbable layer 55 thatmay be adhered to a non-absorbable layer 53 such as ePTFE. Thisdescribes an alternative way to accomplish the attachment of theplurality of hollow members to the sheet component.

[0042] The following examples are provided for illustrative purposesonly as examples of particular embodiments of the described invention.As such, they are not intended to be limiting.

EXAMPLE 1

[0043] This example describes the construction of a multiple tube herniarepair device of the present invention as shown in FIG. 1. A triblockcopolymer of 67%/33% PGA:TMC (w/w) was acquired from US Surgical(Norwalk Conn.) and formed into a self-cohering web as generally taughtby Hayes in U.S. Pat. No. 6,165,217. Sheets of this copolymer webmaterial were formed into the 3 component types used in the constructionof this device.

[0044] A first component used for making this device was a tube formedfrom the self-cohering web sheets that had an area density ofapproximately 8-10 mg/cm² and a thickness of approximately 0.3 mm. Thefirst step in making a tube was to cut an approximately 25 mm wide stripof the self-cohering web material from a piece of “unset” web sheetperpendicular to the belt direction used in forming the web. This stripof “unset” web material was then wrapped lengthwise around anapproximately 5 mm diameter stainless steel rod into a “cigarette roll”having an exposed edge at the surface of the resulting tube extendingalong the length of the tube. This material then self-cohered (asgenerally taught by Hayes in U.S. Pat. No. 6,165,217) at the overlappingportion of the “cigarette roll” to form a 5 mm diameter tube that wasapproximately 150 mm long. The strip of “unset” web material wrappedaround the stainless steel rod was then placed into a Baxter ScientificProducts (McGaw Park Ill.) constant temperature oven, model DK-43, forapproximately 30 minutes at 75° C. to “set” the web. The stainless steelrod and “set” web material were then removed from the oven and allowedto cool. After cooling, the tube formed from the now “set” web materialwas slipped off of the stainless steel rod. Both ends of the “set” webtube were then trimmed leaving a tube that was approximately 90 mm long.Each tube was then placed onto a cutting die to create the notches 24shown in FIG. 1B. A piece of 0.05 mm thick Mylar® sheet (DuPont Company,Wilmington Del.) was placed over the tube to protect it fromcontamination. A lightweight plastic-faced mallet was then used tolightly tap onto the tube through the Mylar® sheet to cut out twonotches 24 and centering hole 26 with the cutting die. Multiple tubeswere made using these methods.

[0045] Another component used in making this device was a disc-shapedplanar sheet of approximately 38 mm in diameter. This disc-shaped planarsheet was made by first taking two 50 mm square sheets of the “unset”self-cohering web material, each with an area density of approximately19 mg/cm² and approximately 1 mm thick. The two sheets were then stackedand placed in a restraining frame fitted about the perimeter of thestacked sheets. The restrained web material was then put into the BaxterScientific Products constant temperature oven for approximately 30minutes at 75° C. to bond the two pieces together to create a thickersheet and to “set” the web. After letting the web material cool to roomtemperature, a disc was cut using an approximately 38 mm diametercircular cutting die punch.

[0046] A third component used in making this device was a band formedfrom an approximately 19 mm wide strip of copolymer web material. Thiscopolymer web strip had an area density of approximately 6-8 mg/cm² anda thickness of approximately 0.3 mm. This was made by rolling the stripof “unset” self-cohering web material into a tube and then holding theoverlapped ends together to allow for self-cohering. The unset webmaterial was then put into a Baxter Scientific Products constanttemperature oven for approximately 30 minutes at 75° C. The resultingband was approximately 19 mm in diameter.

[0047] The device was then assembled by taking the disc first andcentering it on a centering pin extending from the center of the surfaceof an assembly fixture. Then six of the tubes with notches and centeringholes were placed on top of the disc, also centering them on thecentering pin. The tubes were arranged so that they were equally spacedradially. The assembly was then placed onto a Branson model 8400ultrasonic welder (Branson Sonic Power Co., Danbury Conn.). Theultrasonic welder had a Branson catenoidal horn, model 609-010-020 andan approximately 7.6 mm diameter tip that had an approximately 3.2 mmhole in the center to accommodate the centering pin of the assemblyfixture. The ultrasonic welder also had a 1: 0.6 booster. The downstopwas set at approximately 0.4 mm with the downspeed set at number 4.Pressure was set at approximately 0.08 MPa with the trigger set atnumber 2; time was set to 0.2 seconds and the hold duration set at 1.0seconds.

[0048] The ultrasonic welder was shut and activated 3 times for eachdevice. After ultrasonic welding, the six tubes were securely attachedto the disc-shaped sheet. The tubes were then folded up so that theywere oriented to be substantially perpendicular to the sheet component.The band component was then placed around the tubes to hold them in abundled configuration wherein the tubes were substantially parallel toeach other along their lengths. Four slits, spaced equally apart, werethen cut into the disc approximately three quarters of the way from theperimeter of the disc to the center to facilitate insertion on thedevice into a hernia defect site.

EXAMPLE 2

[0049] This example describes the construction of a corrugated tubehernia repair device of the present invention as shown in FIG. 4. Atriblock copolymer of 50% PGA:TMC (w/w) was made and formed into aself-cohering web as generally taught by Hayes in U.S. Pat. No.6,165,217. Sheets of this copolymer web material were formed into someof the components used in the construction of this device. Othercomponents were made from expanded polytetrafluoroethylene (ePTFE) andfrom an absorbable polymer adhesive, as described below.

[0050] A corrugated sheet was made by first placing a piece of the“unset” PGA:TMC web sheet (approximately 100 mm square, about 0.2 mmthick having and having an area density of approximately 4-6 gm/cm²)onto a piece of PeCap® polyester screen, product number 7-1000/45 (SefarAmerica, Monterey Park Calif.) material. This screen material, by virtueof its surface texture, was used to restrain the web material fromdimensional change during the “setting” process. A fixture approximately125 mm square was then placed onto the surface of the web sheet. Thefixture was provided with a set of multiple parallel rods with all oftheir centerlines in the same plane, the rods being of approximately 2.4mm diameter and spaced 5.3 mm center-to-center. These rods acted asmandrels for forming the hollow members of the corrugation.

[0051] A second piece of “unset” web material of the same type as thefirst and of approximately the same dimensions was then placed on top ofthe multiple parallel rod fixture. Unsecured rods of approximately thesame diameter as the rods in the fixture were then placed on top of thesecond piece of “unset” web material, between the parallel rods of theunderlying fixture. These unsecured rods were individually pushed downuntil they were in the same plane as the parallel rods of the underlyingfixture. The result was that the second piece of “unset” web materialnow formed the hollow members of the corrugated sheet as it assumed aconvoluted shape with self-cohering contact points on the bottom pieceof “unset” web material. Another piece of PeCap® polyester screen wasplaced on top of the upper piece of “unset” web material to restrain itfrom dimensional changes during the “setting” process. An aluminum platewas placed on top of the polyester and then a weight was placed on topof the entire assembly. The assembly was then placed into an oven at 80°C. for 30 minutes to “set” the web material. After “setting” in theoven, the web material was allowed to cool and then removed from thefixture of multiple parallel rods.

[0052] Another component used in making this device was a sheetcomponent with a fillet and band for accepting a rolled up piece ofcorrugated web material. The first step in making this sheet componentwas to provide a piece of “unset” web sheet material approximately 50 mmsquare. A circular cutting die was used to cut an approximately 13 mmdiameter hole in the center of it. A 19 mm diameter aluminum rod,approximately 150 mm long, was then fixtured to stand perpendicularly ona flat aluminum plate. The piece of “unset” web material with a hole inits center was then pushed over the aluminum rod. Since the hole in the“unset” web was smaller than the diameter of the aluminum rod, andbecause the “unset” web material was deformable, the difference indiameters between the hole in the web material and the aluminum rodproduced a flared hole in the “unset” web. The aluminum rod and webmaterial were then placed into an oven at 80° C. for 30 minutes to “set”the web material. After allowing the web material to cool, it wasremoved from the aluminum rod. The flared hole in the “set” web materialformed a combined fillet and band (as in FIG. 6) for accepting thecorrugated web material. The piece of “set” web material with the flangewas then adhered to a piece of ePTFE material by using an absorbableadhesive. The adhesive was made from a mixture of poly(85%d,l-lactide-co-15% glycolide) (by mole; abbreviated as 85% d,l-PLA:15%PGA) mixed 1:4 by weight in acetone. It is apparent that this devicecould be made without the ePTFE layer.

[0053] Barb components (FIG. 4, reference no. 42) were individuallyformed by taking a piece of “unset” PGA:TMC web material approximately65 mm long×13 mm wide and wrapping this lengthwise around a suitablytapered mandrel chosen to shape the downwardly-angled barb. The strip of“unset” web material was temporarily restrained to the mandrel by usinga piece of PTFE pipe tape. The tapered mandrel and restrained “unset”web material were then put into an oven at approximately 80° C. forapproximately 30 minutes to “set” the web material. After the webmaterial was “set” in the oven, it was removed from the mandrel. Cutoutswere then made to the center region of the now tapered band to createflanges 44. The device was then assembled by taking the corrugated sheetand rolling it into a tube. Some of the absorbable adhesive was appliedto the circumference of one end of this tube and also to the walls ofthe filleted band portion to be attached to the sheet component. The endof the tube with adhesive on it was then inserted in a perpendicularorientation into the filleted band portion of the sheet component.Absorbable adhesive was then applied to the interiors of a pair ofanchoring barbs, after which they were immediately fitted over thecircumference of the plug component.

EXAMPLE 3

[0054] This example describes a method used to alter the stiffness andrate of bioabsorption of a bioabsorbable device. A solution was made bymixing 65% d,l-PLA:35% PGA available from Birmingham Polymers(Birmingham Ala.) in a 1:10 ratio by weight with acetone. A device asdescribed in Example 1 was dipped into this solution which imbibed intothe structure of the device, and then allowed to air dry. The resultingcoated device was stiffer than prior to imbibing. Alternatively, thissolution could be sprayed onto devices to achieve similar effects. Othercopolymer ratios can also be used to vary the stiffness and rate ofbioabsorption. Also, other ratios of polymer:acetone can be used to varythe final amount of polymer imbibed into or sprayed onto the structureof the device.

[0055] While the principles of the invention have been made clear in theillustrative embodiments set forth herein, it will be obvious to thoseskilled in the art to make various modifications to the structure,arrangement, proportion, elements, materials and components used in thepractice of the invention. To the extent that these variousmodifications do not depart from the spirit and scope of the appendedclaims, they are intended to be encompassed therein.

We claim:
 1. An implantable hernia repair device comprising a plurality of substantially hollow members each having two ends, wherein said hollow members are attached to a substantially planar base member and at least one of the ends is open.
 2. The device of claim 1 comprising a bioabsorbable material.
 3. The device of claim 2 wherein said bioabsorbable material comprises polyglycolic acid.
 4. The device of claim 3 wherein said bioabsorbable material comprises trimethylene carbonate.
 5. The device of claim 1 comprising a non-bioabsorbable material.
 6. The device of claim 5 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 7. The device of claim 1 comprising a bioabsorbable material and a non-bioabsorbable material.
 8. The device of claim 7 wherein said bioabsorbable material comprises polyglycolic acid
 9. The device of claim 8 wherein said bioabsorbable material comprises trimethylene carbonate.
 10. The device of claim 7 wherein said bioabsorbable material comprises trimethylene carbonate.
 11. The device of claim 7 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 12. The device of claim 8 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 13. The device of claim 9 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 14. The device of claim 10 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 15. The device of claim 1 wherein said substantially hollow members comprise a bioabsorbable material.
 16. The device of claim 15 wherein said bioabsorbable material comprises polyglycolic acid
 17. The device of claim 16 wherein said bioabsorbable material comprises trimethylene carbonate.
 18. The device of claim 15 wherein said bioabsorbable material comprises trimethylene carbonate.
 19. The device of claim 15 wherein said substantially planar base member comprises a non-bioabsorbable material.
 20. The device of claim 19 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 21. The device of claim 16 wherein said substantially planar base member comprises a non-bioabsorbable material.
 22. The device of claim 21 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 23. The device of claim 17 wherein said substantially planar base member comprises a non-bioabsorbable material.
 24. The device of claim 23 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 25. The device of claim 18 wherein said substantially planar base member comprises a non-bioabsorbable material.
 26. The device of claim 25 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 27. The device of claim 1 wherein said substantially planar base member comprises a non-bioabsorbable material.
 28. The device of claim 27 wherein said non-bioabsorbable material comprises polytetrafluoroethylene.
 29. The device of claim 27 wherein said substantially planar base member further comprises a bioabsorbable material.
 30. The device of claim 28 wherein said substantially planar base member further comprises a bioabsorbable material.
 31. The device of claim 28 wherein said bioabsorbable material comprises polyglycolic acid.
 32. The device of claim 29 wherein said bioabsorbable material comprises trimethylene carbonate.
 33. The device of claim 29 wherein said bioabsorbable material comprises polyglycolic acid. 